Effects of race and ethnicity on perinatal outcomes in high-income and upper-middle-income countries: an individual participant data meta-analysis of 2 198 655 pregnancies
Authors: Jameela Sheikh, John Allotey, Tania Kew, Borja M Fernández-Félix, Javier Zamora, Asma Khalil, Shakila Thangaratinam, Mali Abdollahain, Ary I. Savitri, Kjell Åsmund Salvesen, Sohinee Bhattacharya, Cuno S.P.M. Uiterwaal, Annetine C. Staff, Louise Bjoerkholt Andersen, Elisa Llurba Olive, George Daskalakis, Maureen Macleod, Baskaran Thilaganathan, Javier Arenas Ramírez, Jacques Massé, Francois Audibert, Per Minor Magnus, Line Sletner, Ahmet Baschat, Akihide Ohkuchi, Fionnuala M. McAuliffe, Jane West, Lisa M. Askie, Fionnuala Mone, Diane Farrar, Peter A. Zimmerman, Luc J.M. Smits, Catherine Riddell, John C. Kingdom, Joris van de Post, Sebastián E. Illanes, Claudia Holzman, Sander M.J. van Kuijk, Lionel Carbillon, Pia M. Villa, Anne Eskild, Lucy Chappell, Federico Prefumo, Luxmi Velauthar, Paul Seed, Miriam van Oostwaard, Stefan Verlohren, Lucilla Poston, Enrico Ferrazzi, Christina A. Vinter, Chie Nagata, Mark; Brown, Karlijn C. Vollebregt, Satoru Takeda, Josje Langenveld, Mariana Widmer, Shigeru Saito, Camilla Haavaldsen, Guillermo Carroli, Jørn Olsen, Hans Wolf, Nelly Zavaleta, Inge Eisensee, Patrizia Vergani, Pisake Lumbiganon, Maria Makrides, Fabio Facchinetti, Evan Sequeira, Robert Gibson, Sergio Ferrazzani, Tiziana Frusca, Ernesto A. Figueiró-Filho, Olav Lapaire, Hannele Laivuori, Jacob A. Lykke, Agustin Conde-Agudelo, Alberto Galindo, Alfred Mbah, Ana Pilar Betran, Ignacio Herraiz, Lill Trogstad, Gordon G.S. Smith, Eric A.P. Steegers, Read Salim, Tianhua Huang, Annemarijne Adank, Jun Zhang, Wendy S. Meschino, Joyce L. Browne, Rebecca E. Allen, Fabricio Da Silva Costa, Kerstin Klipstein-Grobusch, Jan Stener Jørgensen, Jean-Claude Forest, Alice R. Rumbold, Ben W. Mol, Yves Giguère, Wessel Ganzevoort, Anthony O. Odibo, Jenny Myers, SeonAe Yeo, Helena J. Teede, Francois Goffinet, Lesley McCowan, Eva Pajkrt, Bassam G. Haddad, Gustaaf Dekker, Emily C. Kleinrouweler, Édouard LeCarpentier, Claire T. Roberts, Henk Groen, Ragnhild Bergene Skråstad, Seppo Heinonen, Kajantie Eero, Louise C. Kenny, Dewi Anggraini, Athena Souka, Jose Cecatti, Ilza Monterio, Arri Coomarasamy, Melanie Smuk, Athanasios Pillalis, Francesca Crovetto, Renato Souza, Lee Ann Hawkins, Rinat Gabbay- Benziv, Richard Riley, Kym Snell, Lucinda Archer, Francesc Figuera, Marleen van Gelder
Journal: The Lancet (2022)

BackgroundExisting evidence on the effects of race and ethnicity on pregnancy outcomes is restricted to individual studies done within specific countries and health systems. We aimed to assess the impact of race and ethnicity on perinatal outcomes in high-income and upper-middle-income countries, and to ascertain whether the magnitude of disparities, if any, varied across geographical regions.MethodsFor this individual participant data (IPD) meta-analysis we used data from the International Prediction of Pregnancy Complications (IPPIC) Network of studies on pregnancy complications; the full dataset comprised 94 studies, 53 countries, and 4 539 640 pregnancies. We included studies that reported perinatal outcomes (neonatal death, stillbirth, preterm birth, and small-for-gestational-age babies) in at least two racial or ethnic groups (White, Black, south Asian, Hispanic, or other). For our two-step random-effects IPD meta-analysis, we did multiple imputations for confounder variables (maternal age, BMI, parity, and level of maternal education) selected with a directed acyclic graph. The primary outcomes were neonatal mortality and stillbirth. Secondary outcomes were preterm birth and a small-for-gestational-age baby. We estimated the association of race and ethnicity with perinatal outcomes using a multivariate logistic regression model and reported this association with odds ratios (ORs) and 95% CIs. We also did a subgroup analysis of studies by geographical region.Findings51 studies from 20 high-income and upper-middle-income countries, comprising 2 198 655 pregnancies, were eligible for inclusion in this IPD meta-analysis. Neonatal death was twice as likely in babies born to Black women than in babies born to White women (OR 2·00, 95% CI 1·44–2·78), as was stillbirth (2·16, 1·46–3·19), and babies born to Black women were at increased risk of preterm birth (1·65, 1·46–1·88) and being small for gestational age (1·39, 1·13–1·72). Babies of women categorised as Hispanic had a three-times increased risk of neonatal death (OR 3·34, 95% CI 2·77–4·02) than did those born to White women, and those born to south Asian women were at increased risk of preterm birth (OR 1·26, 95% CI 1·07–1·48) and being small for gestational age (1·61, 1·32–1·95). The effects of race and ethnicity on preterm birth and small-for-gestational-age babies did not vary across regions.InterpretationGlobally, among underserved groups, babies born to Black women had consistently poorer perinatal outcomes than White women after adjusting for maternal characteristics, although the risks varied for other groups. The effects of race and ethnicity on adverse perinatal outcomes did not vary by region.FundingNational Institute for Health and Care Research, Wellbeing of Women.